Base32 API

Convert UTF-8 text to RFC 4648 Base32 and decode valid Base32 text with a scriptable HTTP endpoint.

Try the Base32 API

POST /api/v1/base32/

Send request transmits this input to the API server. The online tool processes input in your browser.

Request parameters

ParameterTypeRequiredRules
textstringYesPlain text or RFC 4648 Base32. Maximum: 16384 code points.
operationstringNoEncode UTF-8 text or decode an encoded UTF-8 string. Values: encode, decode. Default: "encode".
paddingbooleanNoInclude = padding when encoding. Default: true.

Response fields

A successful response is {"ok":true,"data":{…}}. These fields are inside data.

result · string
The converted text. Empty input can produce an empty result.

When Base32 is useful

Base32 uses letters and a small digit set, which can be convenient when exchanging encoded text through systems that handle punctuation poorly. This API implements the RFC 4648 alphabet. It is not Crockford Base32, Base32hex or a TOTP secret-management service. Choose the variant your receiving application expects before integrating.

Case and padding rules

The encoder returns uppercase letters and includes padding by default. The decoder also accepts lowercase letters, but it rejects whitespace, digits outside 2–7, invalid padding lengths and unused trailing bits. A successful response contains decoded UTF-8 text; arbitrary binary data is outside this endpoint’s contract.

cURL, JavaScript and Python examples

Encode

The standard alphabet uses A–Z and 2–7.

cURL
curl --fail-with-body --request POST 'https://www.base64.sh/api/v1/base32/' \
  --user-agent 'Base64.sh API example/1.0' --header 'Content-Type: application/json' \
  --data-raw '{"text":"foo"}'
JavaScript
const response = await fetch("https://www.base64.sh/api/v1/base32/", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
  "text": "foo"
})
});
if (!response.ok) throw new Error(await response.text());
console.log(await response.json());
Python
import json
from urllib.request import Request, urlopen

payload = json.loads("{\n  \"text\": \"foo\"\n}")
request = Request(
    "https://www.base64.sh/api/v1/base32/",
    data=json.dumps(payload, ensure_ascii=False).encode("utf-8"),
    headers={"Content-Type": "application/json", "User-Agent": "Base64.sh API example/1.0"},
    method="POST",
)
with urlopen(request, timeout=15) as response:
    print(json.load(response))

Response · HTTP 200

{
  "ok": true,
  "data": {
    "result": "MZXW6==="
  }
}

Decode

Padded and canonical unpadded forms are accepted.

cURL
curl --fail-with-body --request POST 'https://www.base64.sh/api/v1/base32/' \
  --user-agent 'Base64.sh API example/1.0' --header 'Content-Type: application/json' \
  --data-raw '{"text":"MZXW6===","operation":"decode"}'
JavaScript
const response = await fetch("https://www.base64.sh/api/v1/base32/", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
  "text": "MZXW6===",
  "operation": "decode"
})
});
if (!response.ok) throw new Error(await response.text());
console.log(await response.json());
Python
import json
from urllib.request import Request, urlopen

payload = json.loads("{\n  \"text\": \"MZXW6===\",\n  \"operation\": \"decode\"\n}")
request = Request(
    "https://www.base64.sh/api/v1/base32/",
    data=json.dumps(payload, ensure_ascii=False).encode("utf-8"),
    headers={"Content-Type": "application/json", "User-Agent": "Base64.sh API example/1.0"},
    method="POST",
)
with urlopen(request, timeout=15) as response:
    print(json.load(response))

Response · HTTP 200

{
  "ok": true,
  "data": {
    "result": "foo"
  }
}

Invalid request example

{
  "text": "M1======",
  "operation": "decode"
}

HTTP 400

{
  "ok": false,
  "error": {
    "code": "INVALID_INPUT",
    "message": "Invalid RFC 4648 Base32 alphabet."
  }
}

Limits and error handling

Requests require Content-Type: application/json and a UTF-8 JSON object. The body limit is 32 KiB (32,768 bytes), text fields allow up to 16,384 Unicode code points unless a smaller limit is listed, and responses are limited to 256 KiB. Unknown parameters and unpaired Unicode surrogates in parameter strings are rejected. Send inputs in the request body, not query parameters.

Anonymous access is limited to approximately 60 POST requests per minute per IP address, shared across endpoints in each Cloudflare location. Shared networks share the allowance. Counters are eventually consistent, not a guaranteed global quota. On HTTP 429, wait for the Retry-After interval before retrying; avoid immediate retry loops.

Programmatic clients should send an identifying User-Agent, as shown in the cURL and Python examples. Browser fetch supplies its own header. Cloudflare may reject a generic or missing agent before the API runs; an edge-generated 403 can be plain text or HTML rather than the JSON envelope. See Cloudflare error 1010.

400 · Invalid input
Malformed JSON, missing fields, unsupported options or invalid encoded text. Correct the input before retrying.
403 · Edge request blocked
Check the User-Agent and the Cloudflare error response before retrying.
404 · Unknown endpoint
Use a documented /api/v1/{tool}/ endpoint.
405 · Method not allowed
Use POST. OPTIONS is supported for browser CORS requests.
413 · Size limit exceeded
Reduce the request size or the generated output.
415 · Unsupported media type
Set Content-Type: application/json.
429 · Rate limited
Wait at least the Retry-After number of seconds.
500 / 503 · Service unavailable
Retry later with bounded backoff. Availability is not guaranteed.

API data processing

API inputs are sent over HTTPS and processed in memory by a Cloudflare Worker. The application does not persist submitted text or deliberately log request bodies, and API responses use Cache-Control: no-store. Cloudflare may process network metadata under its own policies. For local processing, use the corresponding browser tool. See the privacy policy.